Exploring the universe

ExoplanetHunter Android App Version 2 Beta

A new version of the Android application Exoplanet Hunter has been released. The android application has been ported to the framework React Native developed by facebook.

React Native is a framework for building native mobile apps using JavaScript and this will allow us to easily build cross platform applications for IOS, android and Web. This update is just for Android but future updates including more platforms will come.

The app is available in two languishes English and Swedish. Compered to the old version the user interface has been improved.

For new users not familiar with the old application here comes instructions on how the application is used:

The app has four sections Planet list shows all planets ordered by last discovered  date. Notice that the old search feature is not gone. If you click the settings gear in the upper right corner you will find two options.

Search and Dashboard in the search settings you will be able to change sort order and filter exoplanets by

  • Distance (light years)

  • Planet Mass Class (mercurian, subterran, terran, superterran, neptunian, or jovian)

  • Planet Composition Class (iron, rocky-iron, rocky-water, water-gas, gas)

  • Planet Atmosphere Class (none, metals-rich, hydrogen-rich)

  • Planet habitable zone classification (hot, warm, or cold).

The gear will be red marked if a selection is active and is white marked if it is cleared.

The Dashboard  will contain information number of discovered Exoplanets and number of habitable planets. More detailed statistics regarding exoplanets in this section is planned for in future releases. If you select a planet in the list you will go to an information page about the planet. Notice this text is autogenerated and automaticity fetched from the PHL database. We never manually look for this information online and write about exoplanets.

Read more about PHL exoplanet data catalog by visiting their website at HEC: Data of Potentially Habitable Worlds‎ 

The tab navigation will feature planet information page and the star information page:

If one click the 3D button a simulation for solar system will be shown

This is generated using SVG and this is a feature that also is planned for the website in the future. The system is zoomable and the planets are clickable and will take you to the information page for the planet that is clicked. The red line and blue line marks the beginning and the end of the stars habitable zone where alien life could exist.

The section earth-like planets will take you to categories for different habitable zones. Planet Earth Similarity Index (ESI) is used for identify possible habitable planets (ESI > 0.7).

The constellation page will list all constellations and the solar systems in each constellation clicking on the star will take you to the simulation of that system.

The last section will be the starmap.

On map initiation will begin at declination 37.87 degree and right ascension 18 hours in the search range area of the Kepler telescope between the constellations Lyra, Cygnus and Drago.

Potential habitable exoplanets will be shown on the map and will be clickable and take the user to the solar system simulation. The map will be draggable at initiation. By clicking the gps icon at the right corner will activate the phones sensors. Accelerometer and magnetometer will be used to pinpoint the location of the planet from the phones orientation using the altitude and azimuth angle of the device. The time shown in the clock will be the time reckoned from the motion of the earth  relative to the distant stars. This is called the sidereal time.

This version is still beta and i can be downloaded at google play. Service will be found under the section api and will replace the old not updated service.

About us

Exoplanet hunter is an application that provides the user with information about scientific discoveries about Exoplanets the project consist of a web application and an Android application.

About the author and developer

Göran Bäcklund is a Swedish physicist and software developer. Göran took his master of science from Linne university in Vaxjo in 2011 his major was computational fluid dynamics. He works as a software developer with projects involving applications used for visualization and simulations of scientific weather data. He has a long time interest in cosmology and amateur astronomy. 

visit on linkedin

Project Background

I got the idea to develop an application for exoplanets during an assignment in a cosmology course. The assignment was to investigate if there were any open data API containing information about exoplanets. Later I developed one of my own using the PHL's Exoplanets Catalog. The first API was built with PHP using the Laravel framework and the first Android application was released in June 2013.

The purpose was to build a good portfolio app, that people interested in science could use to increase their knowledge.

Later the project was forgotten until the beginning of 2018 when I decided to port the old app to React native and .Net Core. Because I use these techniques in my work as a software developer.   

I will continue the project in my spare time, and I will develop some new really awesome features. In the future, the app will also support more platforms. Meanwhile, I will update this website with articles about cosmology and astronomy focusing on exoplanets.  

About the API

The data is provided by the Planetary Habitability Laboratory (PHL) the University of Puerto Rico at Arecibo and can be found here: phl.upr.edu 

The API is using OData protocol that allows for logical querying capabilities. E.g if you want to find habitable planets "$filter= Habitable eq true". Find planet with name 14 And b "$filter=Name eq '14 And b’". Read more here: msdn.microsoft.com. Skip and top E.g takes 30 and skips 10 "$top=30 $skip=10". Order by ascending discovery year $orderby=Disc_Year asc.

About the web

The client app is built with the javascript framework react and semantic UI. There are three sections on the site:

  • Catalog a section where you can browse all confirmed Exoplanets. It is possible to filter for just habitable planets or search for a specific planet name. You can visit information pages about the planet and the star and see you can see a 3D simulation of each solar system.
  • Map in this section we have an interactive star map of all the 88 modern constellations. And all habitable planets are shown as markers in the map. The map is using Leaflet
  • Chart  Hertzsprung-Russell diagram the bubble chart is a plot of luminosity against the temperature of the star for all stars that have exoplanets. The charts are using Amchart

About the app

We live in one of the most exciting times ever, hundreds of exoplanets have been found. An extrasolar planet, or exoplanet, is a planet outside our Solar System. Even planets very similar to our own Earth have been confirmed which raises questions about the existence of extraterrestrial life. The purpose of the application is to give the user a comprehensive and accurate overview over discovered exoplanets.

  • Easy to read information pages for all found exoplanets
  • The application shows a 3D simulation of each solar system
  • Search for the planets locations in the sky by using GPS and the sensors of the phone
  • Completely Free!


Network communication: Full network access, Your location: Approximate (network-based) location, mock location sources for testing, precise (GPS) location


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